Create rake task for docs CODEOWNERS

What does this MR do?

Please do not merge this work until the TW leadership team can review it.

Codeowners for documentation is complicated. We specify the stage and group that owns each file, but we don't have a way of referencing the actual technical writer for each group, and adding them to the CODEOWNERS file.

Attempts to create a tw namespace for rake tasks (so the Technical Writing team doesn't collide with other teams) and a codeowners task (thus bundle exec rake tw:codeowners) to create a raketask that automates the generation of a list of docs-with-owners, and the TW.

Related issues

These issues and MRs describe the evolution of the CODEOWNERS project for the Technical Writing team, from the initial idea through multiple (!) iterations to a finished product. These links may have been added significantly after this issue or merge request was closed, so they may describe parts of the process before or after this work.

• Related to Create rake task for docs CODEOWNERS (!77715 - merged) where Amy had an idea
• Related to Update CODEOWNERS to include TW assignments for... (!77606 - merged) where we asked for the raw output of the Rake task to be added into the CODEOWNERS file. This rake task would give the TW team a way to periodically generate a full list of owned pages.
• Related to Expand CODEOWNERS with more documentation DRIs (#349587 - closed) where Marcel noted many pages needed a DRI declared
• Related to Update CODEOWNERS to include TW assignments for... (!77606 - merged) where we started manually shortening the results
• Related to Refine how to run batch updates for the CODEOWN... (technical-writing#668 - closed) where we started figuring out how to run batch updates
• Related to Codeowners: Assign TW with more than 50% page o... (#375783 - closed) where we started automating the process of shortening and condensing the results
• Related to Document tw::codeowners rake task (technical-writing#598 - closed) where we documented the task
• Related to Release Post 15.7 MVP Nominations (gitlab-com/www-gitlab-com#14283 - closed) where Niklas was nominated as MVP for the months of iteration needed to bring this script to a full, workable state

Author's checklist

• Consider taking the GitLab Technical Writing Fundamentals course.
• Follow the:
  • Documentation process.
  • Documentation guidelines.
  • Style Guide.
• Ensure that the product tier badge is added to topic's h1.
• Request a review based on:
  • The documentation page's metadata.
  • The associated Technical Writer.

If you are only adding documentation, do not add any of the following labels:

• ~"frontend"
• ~"backend"
• ~"type::bug"
• ~"database"

These labels cause the MR to be added to code verification QA issues.

Review checklist

Documentation-related MRs should be reviewed by a Technical Writer for a non-blocking review, based on Documentation Guidelines and the Style Guide.

• If the content requires it, ensure the information is reviewed by a subject matter expert.
• Technical writer review items:
  • Ensure docs metadata is present and up-to-date.
  • Ensure the appropriate labels are added to this MR.
  • If relevant to this MR, ensure content topic type principles are in use, including:
    • The headings should be something you'd do a Google search for. Instead of Default behavior, say something like Default behavior when you close an issue.
    • The headings (other than the page title) should be active. Instead of Configuring GDK, say something like Configure GDK.
    • Any task steps should be written as a numbered list.
    • If the content still needs to be edited for topic types, you can create a follow-up issue with the docs-technical-debt label.
• Review by assigned maintainer, who can always request/require the reviews above. Maintainer's review can occur before or after a technical writer review.
• Ensure a release milestone is set.